I have run into this griefer strategy twice myself quite recently. (See snap.) Can't reply to Ayu Sura's post due to odd thread settings, but "me too."
Just past the edge of my land (and a sim border) so I can't eject emitter. Obviously, muting is no good, even if I can find click on one of these bitty little stealth objects, as it continues to pester other visitors.
It's discouraging to read from Ayu that 4 ARs accomplished nothing. Seems to be an attack mode du jour. One-on-one staff intervention is not an efficient or effective solution to the risk. Anyone given any thought to applying the object entry ban to particles? If particles become more a tool of harassment than art, some thought needs to be given to their world-wide physics limits. -JP